docs: def list_instances(self, tags=None, cpus=None, memory=None, hostname=None,
                         disk=None, datacenter=None, **kwargs):
          """Retrieve a list of all dedicated hosts on the account
  
          :param list tags: filter based on list of tags
          :param integer cpus: filter based on number of CPUS
          :param integer memory: filter based on amount of memory
          :param string hostname: filter based on hostname
          :param string disk: filter based on disk
          :param string datacenter: filter based on datacenter
          :param dict \\*\\*kwargs: response-level options (mask, limit, etc.)
          :returns: Returns a list of dictionaries representing the matching dedicated host.
  
          """
          if 'mask' not in kwargs:
              items = [
                  'id',
                  'name',
                  'cpuCount',
                  'diskCapacity',
                  'memoryCapacity',
                  'datacenter',
                  'guestCount',
              ]
              kwargs['mask'] = "mask[%s]" % ','.join(items)
  
          _filter = utils.NestedDict(kwargs.get('filter') or {})
          if tags:
              _filter['dedicatedHosts']['tagReferences']['tag']['name'] = {
                  'operation': 'in',
                  'options': [{'name': 'data', 'value': tags}],
              }
  
          if hostname:
              _filter['dedicatedHosts']['name'] = (
                  utils.query_filter(hostname)
              )
  
          if cpus:
              _filter['dedicatedHosts']['cpuCount'] = utils.query_filter(cpus)
  
          if disk:
              _filter['dedicatedHosts']['diskCapacity'] = (
                  utils.query_filter(disk))
  
          if memory:
              _filter['dedicatedHosts']['memoryCapacity'] = (
                  utils.query_filter(memory))
  
          if datacenter:
              _filter['dedicatedHosts']['datacenter']['name'] = (
                  utils.query_filter(datacenter))
  
          kwargs['filter'] = _filter.to_dict()
          return self.account.getDedicatedHosts(**kwargs)